I was watching a iow tsw2 video while still researching the line and could see on the directionial control foward 1 forward 2 what is the difference between F1 & F2?
One accelerates faster. On a livestream, I think Rivet said they only use the slow one to reduce wear and tear on these old trains.
Forward 2 is there if you want to use it because you can’t break the train in the game. They don’t use it in real life but you can in the game if you want a nice boost to your acceleration. It’s quite a different driving experience in Forward 2.
You can use Forward 2 in the game if you want and improve punctuality. Forward 1 I use as the timetable isn't too crazy with the arrival times.